Dye transfer apparatus and method for processing color motion picture film

ABSTRACT

A method is provided for transferring dye from a dye imbibed matrix film to a receiver film for producing a dye transfer print of a motion picture print. A dye imbibed matrix film and a receiver film are superimposed together in precise registration on a seating apparatus, e.g., a pin belt, to create a two-film sandwich. The two-film sandwich is stripped from the seating apparatus before completing dye transfer, and dye transfer from the matrix film to the receiver film is completed along a pinless, substantially rectilinear film path while maintaining the two-film sandwich in precise registration. For example, a transfer cabinet may be provided that includes a plurality of rollers having a predetermined relationship to one another and defining the substantially rectilinear film path, and the two-film sandwich may be directed along the film path to complete dye transfer.

This is a divisional of application Ser. No. 09/624,359, filed Jul. 24,2000, now U.S. Pat. No. 6,327,027, which is a continuation ofapplication Ser. No. 09/416,923 filed on Oct. 13, 1999, now U.S. Pat.No. 6,094,257, which is a divisional of application Ser. No. 08/925,867,filed on Sep. 9, 1997, now U.S. Pat. No. 6,002,470.

FIELD OF THE INVENTION

The present invention relates generally to film processing, and moreparticularly to an improved system and method for producing printedcopies of motion picture films by dye transfer.

BACKGROUND

In the field of professional cinematography, it is necessary under manycircumstances that two lengths of film be kept in close and accurateregister with one another throughout a lengthy continuous path. Forexample, in manufacturing a dye transfer print of a motion picture fromthree dye imbibed photographic matrices, it is essential that the dyeimage from each individual matrix be transferred to a receiver film innear perfect register with each other in three consecutive steps on acontinuous machine. Further, it is also essential that each individualrecord is transferred completely from matrix to receiver film withsubstantially no movement of one film relative to the other, until suchtime as all of the image has been transferred from each individualmatrix to the common receiver.

Previously, matrix and receiver films were placed in intimate contactwith each other via a multi-stage seating mechanism generally known as aroll tank. While being placed into intimate contact with each other, thetwo films were also seated onto a stainless steel ribbon, known as a pinbelt. The pin belt typically traveled in an orbital path extendingaround and between two or more drums or wheels. The perforations orsprocket holes of the sandwiched films were placed over silver alloypins raised above the flat stainless steel ribbon. Both films remainedfirmly seated on the pin belt for the duration of time needed forcomplete dye transfer from matrix to receiver, generally about thirtyfive seconds.

Because of the time required for complete dye transfer, such pin beltsgenerally had a peripheral length of about 205 feet and were operated atspeeds of about 330 feet per minute. One of the difficulties resultingfrom using such long belts is achieving and maintaining the exacting pintolerances necessary to hold the precise registration needed to producehigh quality prints. In addition, repair and replacement of these longbelts was indeed expensive and difficult. The machinery and methods usedfor dye transfer of color film prints has remained substantiallyunchanged since its original development in the 1920's and 1930's.

To obtain the faster throughput necessary to meet the demand for thelarger quantities of prints required today, the operating speed of a dyetransfer machine must be increased. A larger apparatus requiring alonger pin belt, however, would only magnify the problems of maintainingthe exacting pin tolerances necessary to maintain precise registrationduring dye transfer. The space required for such an apparatus and thecost to manufacture and maintain the pin belt generally render such asystem commercially impracticable.

For these and other reasons, the dye transfer process generally hasbecome less favored than photographic copying processes. Conventionalphotographic copying of a master onto unexposed photographic films, suchas nitrate, acetate, and more recently polyester films, are now widelyused for producing the large number of prints needed for modern theaterdistribution, which can require more than 4,000 prints per film.

Photographic film processing, however, does not provide the precisecolor control of tone scale and color reproduction available using dyetransfer processing, which may result in inferior color rendition inphotographic film prints. Further, photographic film has a greatertendency to fade over time, resulting in a less durable print.

Accordingly, there is a need for an improved system for producing dyetransfer prints of motion pictures that is capable of maintainingprecise registration at high volume production speeds.

There is also, then, a need for a method of producing dye transferprints of films competitively in sufficient quantities for thecontinuously growing need of motion picture theater distribution.

SUMMARY OF THE INVENTION

The present invention is directed to a system for producing printedcopies of films by dye transfer. More particularly, the presentinvention is directed to an apparatus and method for maintainingsandwiched films, comprising a matrix film superimposed onto a receiverfilm, in precise registration during dye transfer, the predominance ofwhich is accomplished without a pin belt.

Generally, a dye transfer apparatus in accordance with the presentinvention includes a roll tank having a first plurality of rollers in apredetermined orientation. The first plurality of rollers is adapted tosuperimpose a blank or receiver film onto a dye-imbibed matrix film in apredetermined registration, i.e. to place the receiver and matrix filmsin intimate contact, thereby creating a two-film “sandwich” for dyetransfer.

The roll tank communicates with a pin belt, which includes a pluralityof pins or teeth on a ribbon traveling in an orbital path. The pinsengage sprocket holes in the two-film sandwich delivered within the rolltank, thereby directing the two-film sandwich along a portion of theorbital path. The pins also have a predetermined spacing therebetweenfor maintaining the two-film sandwich in precise registration as theytravel along the orbital path. A first stripping roller is provided incommunication with the pin belt, which strips the two-film sandwich fromthe pin belt, while maintaining the films in precise registration andwithout adversely affecting the adhesion between the films.

A transfer cabinet then receives the two-film sandwich from the firststripping roller to substantially complete dye transfer. The transfercabinet includes a second plurality of rollers having a predeterminedrelationship to one another, and an elevator mechanism for adjusting thepredetermined relationship. The rollers in the transfer cabinet haverelatively large diameters compared to the other rollers in theapparatus, thereby defining substantially rectilinear paths along theirperimeters. The rollers define a film path along which the two-filmsandwich travels through the transfer cabinet, the two-film sandwichtraveling systematically around a portion of the perimeters of therollers and between the rollers in a predetermined sequence. The rollersalso preferably have substantially uniform, toothless perimeters,thereby allowing the two-film sandwich to travel along the perimetersthereof without requiring sprockets or teeth to engage the two-filmsandwich, while maintaining the films in precise registration andwithout adversely affecting the adhesion between the films.

The elevator mechanism includes one or more servo-motors for preciselyadjusting the position of one or more corresponding rollers within thetransfer cabinet, thereby providing a predetermined tension on thetwo-film sandwich traveling along the film path. The elevator mechanismmay be adjusted manually, or may include one or more sensors formeasuring the actual tension of the two-film sandwich as it travelsalong the film path. Preferably, the transfer cabinet also includes apair of synchronized servo-motors for adjusting the distribution oftension of the two film sandwich, thereby providing additional tensionadjustment, and thereby further maintaining the two-film sandwich inprecise registration and without adversely affecting the adhesionbetween the films.

The transfer cabinet also provides predetermined atmospheric conditions,such as a predetermined temperature and humidity, to promote completedye transfer from the dye imbibed matrix to the receiver film as thetwo-film sandwich travels through the cabinet in a predetermined time.

A second stripping roller, including a third plurality of rollers in apredetermined orientation, is provided in communication with the filmpath of the transfer cabinet. The third plurality of rollers separatethe matrix film from the receiver film after complete dye transfer hasoccurred substantially within the transfer cabinet.

The separated receiver film may then be processed using other apparatusand methods to provide a finished print. For example, the receiver filmmay be directed through a subsequent system similar to that justdescribed to transfer an additional color to the receiver film. Thematrix film may be directed through dying equipment, or a spray dyetank, and followed by a washback system enclosure, in preparation fordye transfer to a subsequent receiver film.

A dye transfer printing system in accordance with the present inventionsubstantially reduces the length of pin belt necessary for an individualdye transfer path, and allows the system to operate at substantiallyhigher speeds than traditional pin belt systems to produce film printsin substantially greater volume in a commercially feasible manner. Forexample, in one aspect, a roll tank in accordance with the presentinvention may include rollers having a predetermined hardness and whichapply a predetermined pressure to the two-film sandwich to promoteadhesion and/or dye transfer at substantially higher speeds thanprevious systems.

In addition, a pin belt in accordance with the present invention mayhave an orbital path or peripheral length substantially less than about200 feet, and preferably about 22 feet. The pin belt includes speciallydesigned and/or arranged pins adapted to facilitate seating andstripping of the films from the pin belt at relatively high speedswithout substantial risk of damaging the films. Thus, the pin belt maybe operated at speeds of about 800 feet per minute or more, andpreferably between about 1,000 and 1,200 feet per minute, withoutsubstantial risk of damaging and/or misaligning the two-film sandwichduring seating and subsequent stripping. These parameters result in thetwo-film sandwich being on the pin belt for not more than about 1 or 2seconds, that is, substantially less than 10% of the about 45-50 secondsgenerally needed for complete dye transfer.

Thus, a dye transfer apparatus in accordance with the present inventionsubstantially completes dye transfer without a pin registration devicesuch as the pin belt, and preferably while the two-film sandwich isdirected along a pinless substantially rectilinear path, such as withinthe transfer cabinet. The film path preferably has a length that issufficiently long such that the two-film sandwich travel through thetransfer cabinet in about 45-50 seconds, thereby allowing complete dyetransfer to occur therein. The substantially rectilinear path defined bythe relatively large diameter rollers and the natural adhesion of thefilms promoted by the tension adjustment provided by the elevatormechanism allow the transfer cabinet to maintain the two-film sandwichin precise registration without the need for pins or sprockets, therebyallowing the films to travel along the film path at substantially higherspeeds than previously available.

Accordingly, a principal object of the present invention is to provide adye transfer apparatus that substantially reduces the length of pin beltneeded to maintain a matrix film and a receiver film in preciseregistration during dye transfer.

It is also an object to provide an improved apparatus and method formaintaining in precise registration a receiver film superimposed onto adye imbibed matrix film as they travel at relatively high speeds along acontinuous path;

It is also an object to provide an improved system for processing dyetransfer prints of professional motion picture films at substantiallyhigher speeds than those available using prior dye transfer systems.

It is also an object to provide an improved roll tank for seating a dyeimbibed matrix film and a receiver film together to facilitate dyetransfer under high speed conditions.

It is also an object to provide an improved pin belt for seatingreceiver and matrix films thereon, and for stripping the films therefromunder high speed conditions.

Other objects and features of the present invention will become apparentfrom consideration of the following description taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view of a dye transfer system in accordancewith the present invention.

FIG. 2 is an elevation view taken along line 2—2 of FIG. 1, showing adye transfer apparatus in accordance with the present invention,including a pin belt and a transfer cabinet.

FIG. 3 is an enlarged view of the roll tank and pin belt of FIG. 2.

FIG. 4 is an elevation view of a machined stripping roller for removinga two-film sandwich from a pin belt.

FIG. 5 is an enlarged view of the transfer cabinet of FIG. 2.

FIG. 6 is a cross-sectional elevation along line 6—6 of FIG. 1 of thetransfer cabinet of FIG. 5.

FIG. 7 is an elevation view of a machined stripping roller forseparating matrix and blank films after dye transfer.

FIG. 8 is an alternate elevation view of the,stripping roller of FIG. 7taken along line 8—8.

FIG. 9 is a cross-sectional view of the transfer cabinet of FIG. 6 takenalong line 9—9.

FIG. 10A is a plan view of a segment of a two-film sandwich on a pinbelt.

FIG. 10B is a side view of the two-film sandwich and pin belt of FIG.10A.

FIG. 10C is an exploded perspective view of the sandwiched film and pinbelt of FIG. 10A.

FIG. 11A is a cross-section of a pair of pins for a pin belt (shown inphantom) in accordance with the present invention.

FIG. 11B is a top view of one of the pins of FIG. 11A.

FIG. 11C is a detail of a pair of pins with a two-film sandwich seatedthereon.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to the drawings, FIG. 1 shows a schematic plan of a dyetransfer system 10 in accordance with the present invention. Generally,the system 10 is used to print a copy of a professional motion pictureusing a three color dye transfer process. A blank or receiver film 12 isprovided into which dye is transferred to create the copied print(called an imbibition dye transfer print or an “IB print”), and a matrixfilm 14 is provided to transfer a colored dye into the blank film 12.The materials and construction of the films for example the polyesterfilm base used, as well as their chemical properties, are known and willnot be addressed herein.

The system 10 includes a continuous path or loop for the matrix film 14and a continuous path for the blank film 12. The matrix film path 14includes equipment for applying dye to the matrix film, namely a dyetank 30, a washback system enclosure 32, and includes a dye transferapparatus 40 for completing dye transfer to the blank film 12.

Turning now to FIGS. 2-9, a dye transfer apparatus 40 in accordance withone aspect of the present invention is shown. The apparatus 40 includesa roll tank 42, a pin belt apparatus 44, a first stripping roller 46, atransfer path cabinet 48, and a second stripping roller 50.

With particular reference to FIG. 3, the roll tank 42 includes a wetsection 52 and a dry section 54. Each section 52, 54 is preferably asubstantially enclosed separate chamber within the roll tank 42connected by openings through which the blank film 12, the matrix film14 and the pin belt 70 (all shown in phantom) may travel. The roll tank42 also includes a plurality of rollers 56-64, preferably havingsubstantially smooth perimeters, rotatably fixed in a predeterminedrelationship within the roll tank 42.

For example, the wet section 52 includes a roller 56 which receives thedye imbibed matrix film 14 and guides it onto the pin belt 70. Roller 58receives the blank film 14 and directs it towards a first pair ofrollers 60. The first pair of rollers 60 cooperatively direct the blankfilm 12 onto the pin belt 70 and superimpose the blank film 12 onto thematrix film 14 in a predetermined registration to create a two-filmsandwich 16 (not shown in FIG. 3). Alternatively, the pre-wet blank film12 may be seated first on the pin belt 70, followed by the matrix film14. The second pair of rollers 62 apply a predetermined pressure tofurther seat the films 12, 14.

The wet section 52 preferably includes conditions that facilitateinitial seating and adhesion of the films 12, 14. For example, water maybe injected or sprayed between the films 12, 14 as they are being seatedonto the pin belt 70. Alternatively, the wet section 52 may be filledwith water into which the films 12, 14 may be totally immersed. Thewater allows the films 12, 14 to move into registration with oneanother, and the subsequent removal of that water under pressure removesentrained air and promotes the natural adhesion of the two-film sandwich16, i.e., the tendency of wet films to adhere substantially to oneanother, to help reduce misalignment and maintain the films 12, 14 inprecise registration.

Preferably, temperature-controlled water, i.e. water that is heated to apredetermined temperature is injected between the films 12, 14 as theyare being placed in intimate contact with one another. For example,water at temperatures of between about 100-110 degrees Fahrenheit, andpreferably about 105 degrees, may be appropriate for this purpose. Inaddition, one or more additives may be provided in the water to promoteadhesion and/or facilitate dye transfer. For example, it may beappropriate to add calcium or a similar material to control waterhardness, e.g. to slightly harden the water injected between the films12, 14.

The dry section 54 includes two pairs of rollers 64 a, 64 b which alsoapply a predetermined pressure to the two-film sandwich 16 and removeexcess water from between the films 12, 14 for optimum dye transfer. Thelocation of the rollers 56-64 within the roll tank 42 and in relation toeach other may be manually and/or automatically adjustable to maintainthe predetermined registration and the predetermined pressure.

Preferably, the relative positions of the pairs of rollers 60-64 arepneumatically controlled to apply the predetermined pressure to thetwo-film sandwich 16, typically between about 12 psi and about 30 psi.For example, the wet section rollers 60, 62, may apply pressures ofbetween about 18-25 psi to the films 16, with about 25 psi presentlybeing most preferred. The dry section rollers 64 a, 64 b may applypressures of between about 10-25 psi, with 25 psi being preferred forthe first pair of rollers 64 a, and 15 psi being preferred for thesecond pair of rollers 64 b.

In addition, the rollers 60-64 also preferably have predeterminedhardnesses to enhance point-to-point contact and to drive out the excesswater and entrained air to further promote optimum adhesion and/or dyetransfer. Generally, the rollers 60-64 have a rigid inner rim (e.g. rim162 on roller 62), which may be furnished from brass or otherconventional material, and an annular tire (e.g. tire 163 on roller 62)furnished from rubber or similar material having a predeterminedhardness. For example, hardnesses of between about 65A and about 85A(Shore Durometer) have been found to be useful for the presentinvention. Preferably, the upper rollers 60, 62, 64 a and 64 bhavehardnesses of about 75A, 65A, 85A and 75A respectively, while the lowerrollers 60, 62, 64 a, and 64 b all preferably have a hardness of about75A. The predetermined hardnesses and pressures of the pairs of rollers60-64 provide improved conditions for maintaining the films 12, 14 inprecise registration during the high speeds of the present dye transfersystem.

With particular reference to FIGS. 2-4, the pin belt apparatus 44 isshown which includes the pin belt 70 and a pair of wheels 74, 76supported by a conventional frame structure 75. The pin belt 70 is anendless ribbon traveling in an orbital path 72 (shown in phantom) aroundand between the two wheels 74, 76. The pin belt 70 is preferablyproduced from stainless steel using known methods and constructions, andhas a periphery defined by said orbital path 72, preferablysubstantially less than about 200 feet, and more preferably betweenabout 18 and about 22 feet in length. The wheel 74 is adjustably mountedto the frame 75 and may freely rotate, while the wheel 76 ismotor-driven, thereby allowing the pin belt to engage the wheels andtravel along the orbital path 72. A weighted rack and pinion apparatus78 allows the location of wheel 74 to be adjusted and substantiallylocked, thereby regulating the distance between the wheels 74, 76 andapplying a predetermined tension to the pin belt 70 proportional to theweight 79. The servo-motor 84 drives the wheel 76, thereby controllingthe speed of the pin belt 70 and applying further desired tension to thetwo-film sandwich 16 traveling along the orbital path 72.

As shown in FIGS. 10A-10C, the pin belt 70 includes a plurality of pinsor teeth 71 substantially permanently attached to or integrally formedon the outer surface of the pin belt 70, preferably being force fitthrough pre-punched openings spaced along the pin belt ribbon.Preferably the pins are spun from coin silver to a predetermined shapeadapted to facilitate the pin belt 70 detachably receiving and engagingperforations or sprocket holes 13 in the two-film sandwich 16. The pins71 also have a predetermined spacing therebetween for substantiallymaintaining the two-film sandwich 16 in precise registration as theytravel along the orbital path 72 (e.g. about 0.187275 inches).

Preferably, the pin belt 70 has a pairs of pins 71 a, 71 b spaced alongthe length of the pin belt 70, the pins within each pair being spacedapart across a width, e.g. about 1.109 inches, of the pin belt 70,thereby corresponding to the two sets of sprocket holes provided onconventional film strips. More preferably, one set of pins 71 a is“full-fitting,” that is, has a shape and size substantially similar tothe corresponding holes 13 in the films 16, while the other set of pins71 b has a substantially smaller size, e.g. smaller width and/or length,thereby promoting stability of the two-film sandwich 16 yet facilitatingtheir removal from the pin belt 70 at relatively high drive speeds.Alternatively, only a single set of pins (not shown) adjacent one edgeof the pin belt 70 may also provide sufficient stability to engage thetwo-film sandwich 16 and maintain the films 12, 14 in preciseregistration.

Turning to FIGS. 11A-11C, a portion of a preferred embodiment of a pinbelt 70 (shown in phantom in FIG. 11A) is shown having a full-fittingpin 71 a adjacent a smaller pin 71 b. The pin 71 a has a substantiallyrectangular shape corresponding to the shape of the sprocket holes 13 ofthe two-film sandwich film 16, preferably having rounded edges. The pin71 a has a substantially domed or mushroom cross-section forfacilitating the seating and stripping of the films 16 on and from thepin belt 70 under high speed conditions. The smaller pin 71 b also has asubstantially rectangular shape and a domed cross-section, althoughsmaller in width and length than the full-fitting pin 71 a.

Preferably, the pins 71 a, 71 b are fastened to the pin belt 70 suchthat the front surfaces 170 a, 171 a are parallel and adjacent to oneanother. Thus, the front surfaces 170 a, 171 a both substantially engagethe leading edge 113 a of the sprocket holes 13 on the two-film sandwich16 to maintain the films in precise registration as they are directedalong the orbital path (not shown) in the direction indicated by arrow180. The rear surface 170 c of the full-fitting pin 71 a substantiallyengages the trailing edge 113 c of the sprocket hole 13, while the rearsurface 171 c of the smaller pin 71 b does not. Similarly, the sidesurfaces 171 b of the smaller pin 71 b do not engage the side edges 113b of the sprocket 13.

For example, the full-fitting pin 71 a may have a height 173 of about0.625 inch, a width 170 a of about 0.110 inch, and a length 170 b ofabout 0.078 inch (corresponding substantially to the width and length ofthe sprocket hole 13). The smaller pin 71 b may have a height 173 ofabout 0.625 inch, a width 171 a of about 0.100 inch, and a length lessthan about 0.073 inch.

Attached to the pin belt machine 44 is the first stripping roller 46which generally includes one or more rollers for stripping or guidingthe two-film sandwich 16 from the pin belt 70. Preferably, the firststripping roller 46 includes a substantially smooth perimeter roller 80which facilitate removing the two-film sandwich 16 from the pins of thepin belt 70.

As can be seen from FIG. 3, the roll tank 42 and the first strippingroller 46 are generally attached to or integrally formed on the pin beltapparatus 44. Preferably, the roll tank 42 is mounted on a central,upper portion of the pin belt apparatus 44, whereby the blank and matrixfilms 12, 14 are directed onto a substantially flat segment of the pinbelt 70. Similarly, it is preferred that the first stripping roller 46be mounted adjacent a flat segment of the pin belt 70 to facilitateremoval of the two-film sandwich 16 therefrom. Thus, the two-filmsandwich 16 preferably travels along only a portion of the orbital path72 between the roll tank 42 and the first stripping roller 46.Alternatively, however, each component may be provided separately or maybe mounted in alternative configurations to that shown withoutsubstantially affecting the operation of the apparatus 40.

Turning now to FIGS. 5-9, the transfer cabinet 48 is shown whichincludes an arrangement of elevator-controlled rollers 86-92 mountedwithin a substantially enclosed cabinet 49. The cabinet 49 includesopenings (not shown) into and out of the cabinet 49 to a continuous filmpath 94 along which the two-film sandwich 16 may be directed, forexample, from the pin belt apparatus 44 into the transfer cabinet 48,and from the transfer cabinet 48 to the second stripping roller 50.

Generally, within the transfer cabinet 48, the rollers 86-92 arerotatably mounted in a predetermined relationship to one another toprovide the continuous film path 94 along which the two-film sandwich 16may travel. The film path 94 defined by the rollers 86-92 should providesufficient length and time for complete dye transfer to occursubstantially within the transfer cabinet 48.

Preferably, the rollers 86, 88, 92 are mounted in banks, sharing commonaxles 96, 98 and support frames 100. Rollers 90 are mountedindependently in banks using support frames 102. In addition, the banksare slightly offset from one another, such that the arrangement ofrollers 86-92 defines one or more substantially helical paths definingthe overall film path 94. Preferably, the arrangement of the rollers86-92 defines a film path 94 having a length substantially higher thanabout 205 feet, preferably between about 600 and about 1,000, and mostpreferably between about 750 and about 900 feet. Thus, the two-filmsandwich 16 remains in the transfer cabinet 48 for between about 45-50seconds, and preferably not more than about 45 seconds, while travelingat drive speeds substantially greater than about 330 feet per minute,preferably between about 800-1,200, and most preferably between about1,000-1,200 feet per minute, or more.

For example, as shown in FIGS. 6 and 9, the transfer cabinet 48preferably includes two similar sets of rollers 86-92, in substantiallyopposite-hand arrangements 104, 106. The banks of rollers 86, 88, 92have 18 rollers each mounted on common axles 96, 98 and frames 100,while banks of rollers 90 have 18 rollers mounted on frames 102. Thefilm path 94 of the transfer cabinet 48 is defined by a series ofsubstantially straight paths extending between the rollers 86-92 whichbegins at a point 94 a where the two-film sandwich 16 enters thetransfer cabinet 48. A first roller 86 a diverts the film path 94vertically along path 94 b to a second roller 90. The film path 94 thenfollows the additional rollers 90, 92 along paths 94 c, 94 d, and 94 eat which point, because of the offset of the banks, the path 94 loopshelically back to roller 86 b adjacent to roller 86 a.

The path 94 then extends helically along the banks of rollers 86, 90,and 92 until roller 90 a. At that point, the path 94 extends along path94 f to roller 90 b in the second arrangement 106. The film path 94 thenfollows paths 94 g, 94 h, and 94 i helically through the secondarrangement 106 of rollers 88-92, until roller 88 a, whereupon path 94 jleads out of the transfer cabinet 48.

In addition, the rollers 86-92 preferably have diameters that aresubstantially larger than the diameters of the rollers used elsewhere inthe apparatus 40 and those used in previous dye transfer systems, forexample substantially larger than about 4 inches, and preferably betweenabout 9 inches and 18 inches. The larger diameters result in theperimeters of the rollers 86-92 defining substantially rectilinearpaths, that is, the perimeters are sufficiently large compared to thethickness of the two-film sandwich 16 that the rollers 86-92 behavesimilarly to a substantially straight path rather than a tightly curvedpath. Thus, the two-film sandwich 16, although traveling helically alongthe film path 94 through the arrangement of rollers 86-92, follows asubstantially rectilinear path. Rollers having diameters of about 11⅞inches are presently most preferred for providing a desiredsubstantially rectilinear path.

In addition, unlike a pin belt, the rollers 86-92 are toothless and havesubstantially uniform perimeters, that is, they have no sprockets forengaging the holes in the two-film sandwich 16. As the two-film sandwich16 travels around the perimeter of a relatively small diameter roller,the blank and matrix films 12, 14 may have a tendency to shift or slidein relation to one another, thereby compromising the registration neededfor proper dye transfer. Thus, small diameter rollers usually havesprockets to engage the two-film sandwich 16 and maintain the films 12,14 in precise registration. In contrast, as the two-film sandwich 16travels around the perimeters of the rollers 86-92, the films 12, 14 donot tend to slide in relation to one another because of thesubstantially rectilinear paths defined by the relatively largediameters of the rollers 86-92. Thus, the rollers 86-92 do not needsprockets, pins or teeth which may risk damaging the two-film sandwich16.

The transfer cabinet 48 generally also includes an elevator mechanismfor adjusting the predetermined relationship of the rollers 86-92 toprovide a desired or predetermined tension on the two-film sandwich 14traveling along the film path 94. With particular reference to FIG. 6,the elevator mechanism includes a tension drive motor 112 forcontrolling the vertical position of the rollers 90. The tension drivemotor 112 has a roller chain 114 attached thereto which alsocommunicates with a carriage or beam 116. The carriage 116 is asubstantially rigid frame assembly that is slidably attached to rails118, thereby allowing the carriage 116 to be precisely adjustedvertically within the cabinet 49, as the motor 112 drives the chain 114(e.g. between an upper position during operation and a lower positionfor service and maintenance, both of which are shown). The rollers 90are mounted on frames 102 which are attached to the carriage 116 asshown, thus allowing the distance (represented by paths 94 b, 94 d, 94g, and 94 i) between the upper rollers 90 and the lower rollers 86, 88,and 92 to be adjusted, and thereby adjusting the tension of the two-filmsandwich 16 traveling along the film path 94.

The carriage 116 is manually controlled, thereby allowing an operator toadjust the tension and/or to lower the carriage 116 for maintenance.Alternatively, one or more banks or individual rollers may be adjustablewithin the transfer cabinet 48 to provide suitable tension adjustment.In a further alternative, the elevator mechanism may include one or moreinteracting sensors and servo-motors (not shown) which measure actualtension experienced by the two-film sandwich 16 traveling along the filmpath 94, and precisely move one or more rollers in relation to theothers in response to the actual tension measurements. Thus, the sensorsand servo-motors may be used to adjust the actual tension towards thepredetermined tension, thereby further maintaining the films 12, 14 inprecise registration.

In addition, the transfer cabinet 48 includes a pair of synchronizeddrive motors 108, 110. The motors 108, 110 drive the axles 98 of thebank of rollers 86, 88, thereby controlling the distribution of tensionof the two-film sandwich 16 traveling along the film path 94.Preferably, the axles 98 and motors 108, 110 comprise a tangentiallydriven system, as will be familiar to those skilled in the art. Inaddition, while the motor 108 draws the two-film sandwich 16 from thepin belt 70 into the transfer cabinet 48, the motor 110 draws thetwo-film sandwich 16 through the film path 94. Thus, the speed of themotors 108, 110 may be adjusted relative to one another to providefurther tension control of the two-film sandwich 16 traveling along thefilm path 94.

Preferably, the motor 112 applies a relatively high tension to thetwo-film sandwich 16 as it travels along the film path 94, as comparedto when the two-film sandwich 16 travels along the orbital path 72 onthe pin belt 70, thereby enhancing the films 12, 14 remaining in preciseregister within the transfer cabinet 48. For example, the motor 112 mayapply a tension of about 7-8 pounds to the two-film sandwich 16, whilethe two-film sandwich 16 may only be subjected to about 2-3 pounds oftension while on the pin belt 70.

The transfer cabinet 48 is preferably maintained at predeterminedatmospheric conditions for optimizing complete dye transfer in apredetermined time. For example, the chamber within the transfer cabinet48 may be heated to temperature of between about 110 and about 120degrees Fahrenheit, preferably about 112 degrees Fahrenheit, therebyproviding conditions for complete dye transfer to occur in about 45-50seconds. The temperature within the transfer cabinet 48 may be reduced,possibly as low as ambient temperatures, but this may increase the timeneeded for complete dye transfer (i.e. the time that the two-filmsandwich 16 must remain within the transfer cabinet 48), andconsequently increase the required length of the film path 94.Increasing the temperature may shorten the transfer time, but may alsorisk damage to the films as they are separated from each other. Inaddition, temperatures of about 140 degrees and higher may cause thefilms to become brittle and/or to curl at their edges. In addition, thetransfer cabinet 48 is also preferably maintained at a relative humidityof between about 45% and about 50%. Such humidity may facilitatetransporting of the two-film sandwich 16 over the surface of therollers, by reducing friction. Substantially lower humidity conditions,for example around 10 percent or less may cause the films to curl orotherwise damage the films.

Turning now to FIGS. 6-8, the second stripping roller 50 is shown, whichincludes a plurality of rollers arranged in a predetermined orientation.For example, cooperating sprocket 120 and roller 124 are adapted to“strip” or separate the two-film sandwich 16 into the blank film 12(with the dye transferred thereon) and the matrix film 14. The roller124 may be mounted on an adjustable keeper assembly 122, and thesprocket 120 may be driven by a servo-motor 132 to decouple the tensionapplied within the transfer cabinet 48 (e.g. to reduce the tension ofthe two-film sandwich 16 to about 2 pounds) and drive the matrix film14.

The roller 126 then directs the matrix film 14 out of the secondstripping roller 50 and through the matrix film loop 14, as discussedbelow. The sprocket 128 and roller 130 direct the blank film 12 out ofthe second stripping roller 50 for subsequent processing, e.g. to theblank dry box 36 (see FIG. 1). The sprocket 128 has a motor 134connected thereto to drive the blank film 12 after separation from thematrix film 14.

A dye transfer apparatus in accordance with the present invention allowsdye transfer to occur at substantially higher drive speeds thanpreviously available using traditional pin belt systems. For example, ifa drive speed of about 1,000-1,200 feet per minute is desired andconditions are such that the two-film sandwich must remain superimposedin precise register for about 45 seconds, a path length of about 750-900feet is needed. Thus, a traditional pin belt apparatus operating at suchspeeds would have to be hundreds of feet long, requiring substantialspace. In contrast, a transfer cabinet in a dye transfer apparatus inaccordance with the present invention may provide between about 750-900feet of film path length in only about 50 square feet (e.g. a transfercabinet having a foot print of about 10 feet by it 5 feet).

Returning to FIGS. 1 and 2, a system and method of processing a colorprint by dye transfer in accordance with the present invention is shown.Referring first to the matrix portion of the system 10, the matrix film14 is provided in a substantially continuous loop that is fed through aseries of equipment, including a rinse tank 20, a matrix dry box 22, afirst elevator mechanism 24, a matrix change station 26, a secondelevator mechanism 28, a dye tank 30, and a washback tank 32, all ofwhich are substantially conventional. The matrix film 14 is thendirected through a dye transfer apparatus in accordance with the presentinvention, such as the preferred embodiment described above.

The rinse tank 20 sprays water onto the surface of the matrix film 12 toremove any residue remaining thereon from a previous dye transfer cycle.The matrix dry box 22 then dries the rinsed matrix film 14 as it passestherethrough, typically using forced hot air. The matrix film 14 passesthrough the matrix change station 26 which allows the matrix to bechanged-out between cycles and replaced with a new matrix film 14,and/or provides continuity for the matrix film 14 traveling around theloop.

Elevator mechanisms are provided, which include one or more motor-drivenrollers or other driving mechanisms (not shown) for drawing the matrixfilm 14 through the loop, and a plurality of rollers (not shown) in anadjustable relationship to one another for controlling tension on thematrix film 14. For example, as shown, a first elevator mechanism 24draws the matrix film 14 from the dye transfer apparatus 40 through therinse tank 20 and the matrix dry box 24. A second elevator mechanism 28is also provided which draws the matrix film 14 from the matrix changestation 26.

The matrix film 14 then enters the dye tank 30 which includes aplurality of spray nozzles (not shown) for spraying a particular colordye into the surface of the matrix film 14, substantially soaking thesurface of the matrix film 14. The matrix film 14 then travels to thewashback tank 32 which includes a plurality of nozzles (not shown) forspraying water onto the matrix film 14, thereby removing excess dye fromthe surface thereof to control the color ratio of the completed print.Thus, when the matrix film 14 emerges from the washback tank 32, it isproperly dye imbibed and ready for dye transfer into the blank film 12.

Turning now to the blank film portion of the system 10, the blank orreceiver film 12 is directed along a continuous path, including apre-wet tank 34, the dye transfer apparatus 40, and a blank dry box 36.The pre-wet tank 34 sprays water onto the blank film 12 to moisten agelatin or other absorbent material on the surface thereof for receivingdye.

The blank and matrix films 12, 14 are then directed into the roll tank42, where they are superimposed together under a predetermined pressurein a predetermined registration to create the two-film sandwich 16. Thefilms 12, 14 are directed onto the pin belt 70, which guides thempartially around the orbital path 72 thereof. The first stripping roller46 removes the two-film sandwich 16 from the pin belt 70 and directs itinto the transfer cabinet 48.

The two-film sandwich 16 is then directed along the film path 94 (notshown in FIG. 2) defined by the plurality of rollers 86-92 forsufficient time for dye transfer to be substantially completed. Althoughpart of the dye transfer process may occur prior to the transfer cabinet48, it is preferred that substantially all or most of the process occurin the transfer cabinet, rather than on the pin belt 70. Preferably,less than 10% of the time that the blank and matrix films 12, 14 remainin precise contact should occur on the pin belt 70 and/or outside thetransfer cabinet 48.

Thus, the pin belt 70 acts primarily as a seating device, allowing thefilms 12, 14 to be initially superimposed in precise register thereon.The two-film sandwich 16 may then be removed therefrom and directed intoan apparatus, such as the transfer cabinet 48, where dye transfersubstantially occurs without using a registration device, such as pins,which engage the sprocket holes of the films 12, 14 to keep them inprecise registration. Preferably, the transfer cabinet 48 defines achamber that provides substantially stable atmospheric conditions topromote dye transfer in a predetermined transfer time, for example, thepredetermined temperatures and/or humidity discussed above.

The precise register of the two-film sandwich 16 is enhanced throughoutthe orbital path 72 and the film path 94 traveled by promoting theadhesion and controlling the tension of the two-film sandwich 16. Thepins on the pin belt 70 substantially prevent the tensioned two-filmsandwich 16 from misaligning during seating on the pin belt 70. Withinthe transfer cabinet 48, in addition to the substantially rectilinearpath provided by the relatively large diameter rollers 86-92, thetension control of the elevator mechanism protects the adhesion betweenthe two-film sandwich 16 to maintain the films 12, 14 in preciseregistration throughout the film path 94.

The predetermined relationship of the rollers 86-92 may be manuallyand/or automatically adjusted in response to the actual tensionexperienced by the two-film sandwich 16, for example using the tensionmotor assembly 112-116, thereby maintaining the tension substantially ata predetermined tension that promotes the sandwiches films 16 remainingin precise registration. The drive speeds of the synchronized motors108, 110 may also be adjusted to further maintain the distribution ofthe predetermined tension and promote precise register of the two-filmsandwich 16.

Finally, after complete dye transfer has substantially occurred, thesecond stripping roller strips the blank film 12 from the matrix film14. The blank dry box 36 dries the blank film 12 after dye transfer inthe dye transfer apparatus 40, in preparation for continuing on toanother system (not shown), e.g. for transferring an additional color orfor removing the finished print.

Although only a single system 10 and matrix 14 are shown, it will beappreciated by those skilled in the art that three systems 10 aregenerally necessary to produce a finished copy of a motion picture. Onesystem 10 is provided for each color dye (e.g. cyan, magenta, andyellow) being transferred into the blank film 12, the blank film 12running sequentially through each system 10. Thus, a blank film 12 willpass through three dye transfer apparatus 40, with a single color beingapplied within each apparatus 40, thereby producing a three colorfinished print of a film.

While the invention is susceptible to various modifications, andalternative forms, specific examples thereof have been shown in thedrawings and are herein described in detail. It should be understood,however, that the invention is not to be limited to the particular formsor methods disclosed, but to the contrary, the invention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the appended claims.

What is claimed is:
 1. A method for transferring dye from a dye imbibedmatrix film to a receiver film for producing a dye transfer print of amotion picture print, comprising: superimposing a dye imbibed matrixfilm and a receiver film together in precise registration on a seatingapparatus to create a two-film sandwich; stripping the two-film sandwichfrom the seating apparatus before completing dye transfer; andcompleting dye transfer from the matrix film to the receiver film alonga pinless, substantially rectilinear film path while maintaining thetwo-film sandwich in precise registration.
 2. The method of claim 1,wherein the superimposing step comprises engaging sprocket holes in thematrix and receiver films with precisely spaced pins on the seatingapparatus, thereby maintaining the two-film sandwich in preciseregistration.
 3. The method of claim 2, wherein the seating apparatuscomprises a ribbon to which the pins are attached.
 4. The method ofclaim 1, wherein the seating apparatus comprises a plurality of rollersfor cooperatively superimposing the matrix film and the receiver film ina predetermined registration with one another.
 5. The method of claim 1,wherein the superimposing step comprises immersing the matrix film andthe receiver film in water.
 6. The method of claim 1, wherein the stepof completing dye transfer comprises directing the two-film sandwicharound a portion of and between a plurality of sprocketless rollers. 7.The method of claim 1, wherein the two-film sandwich remains on theseating apparatus for less than about 10% of the time to complete dyetransfer from the matrix film to the receiver film.
 8. The method ofclaim 1, wherein the step of completing dye transfer comprises the stepsof: providing a transfer cabinet comprising a plurality of rollershaving a predetermined relationship to one another, the plurality ofrollers having predetermined diameters, thereby defining a substantiallyrectilinear film path; and directing the two-film sandwich along thefilm path.
 9. The method of claim 8, wherein the step of directing thetwo-film sandwich along the film path comprises directing the two-filmsandwich around a portion of and between each of the rollers in apredetermined sequence.
 10. The method of claim 8, wherein the two-filmsandwich is maintained in precise registration during the step ofcompleting dye transfer by adjusting a tension of the films as theytravel along the film path.
 11. The method of claim 10, wherein thetension of the films is adjusted by adjusting the predeterminedrelationship of the plurality of rollers.
 12. The method of claim 1,wherein the step of completing dye transfer comprises heating thetwo-film sandwich to a temperature of about 112 degrees Fahrenheit. 13.The method of claim 1, wherein the step of completing dye transfercomprises subjecting the two-film sandwich to a relative humidity ofbetween about 45% and about 50%.
 14. The method of claim 1, wherein thestep of completing dye transfer takes between about 45 and about 50seconds.